Screen for exhibiting moving pictures



F. W. HOCHSTETTER.

SCREEN FOR EXHIBITING MOVING PICTURES.

APPLICATION FILED APR- 8, I919. I 1 ,389,357. Patented Aug. 30, 1921.

UNITED STATES PATENT orrlcc- FBEDER-ICK W. HOCHSTETTER, OF NEW YORK, N. Y., ASSIGNOR TO H. P. PATENTS AND PROCESSES COMPANY, INC.,

A CORPORATION OF NEW YORK.

SCREEN FOR EXHIBIT'IN G MOVING PICTURES.

Application filed April 8,

T 0 all whom it may concern:

Be it known that I, FREDERICK HooH- STETTER, a citizen of the United States, and a resident of New York, county and State of New York, have invented a certain new and useful Improvement in Screens for Exhibiting Moving Pictures, of which the following is a full, clear, and exact specification.

This in'vention relates to a class of devices adapted to be used for displaying moving pictures. 1

My invention has for its object primarily to provide a screen adaptedto be employed for permitting moving pictures to be exhibited thereon from a rear projection as Well as from a front projection without requiring the use of a ground glass screen, and which is composed of non-combustible materials in order to eliminate to a large extent the danger of fire during the exhibition of the ictures, this form .of screen being very eflihient in causing the animated objects of the pictures to appear in stereoscopic life-like effects as well as being adapted for day light projection, or for projection in the dark. The invention consists mainly of a plate made of transparent gelatinous material in which is incorporated a coagulating substance for converting the transparency of the material to a translucency, and the material composing the translucent plate is tinted with coloring matter serving to soften or tone the harsh high lights of the photography of the pictures especially when moving pictures are being projected.

A further object of the invention is to treat the translucent plate with a clarifying material whereby its translucency may be partially, or entirely converted to a transparency as occasion requires.

With these and other objects in view, the invention will be hereinafter more particularly described with reference to the accompanying drawing which forms a part of this s ecification, and will then be pointed out in t e claims at the end of the description.

In the drawing, Figure 1 is an elevation of one form of screen for exhibiting moving pictures embodying my invention.

Fig. 2 is a section taken on the line IIII of Fig. 1, and

Fig. 3 is a view showing the translucent plate with part of the translucency thereof Specification of Letters Patent.

1919. Serial No. 288,469.

being converted to a partial transparency .by the use of a clarifying material.

The device, or screen for exhibiting moving pictures is in the form of a plate, as 10, made of clear transparent gelatin, for instance in the proportion of one hundred parts dissolved by the employment of heat is desired in a sufiicient quantity of distilled water to produce a mass of suitable consistency so that when cooled it will harden to a tenacious plate-like body.

\Vhile the gelatinous mass is in a soft state its transparency is converted to a translucency, as at 11, by incorporating thereinto one or more coagulating substances, such as bromid of potassium one hundred parts, and iodid of potassium fifteen parts, these alkalis being firstdissolved in a quantity of distilled water to form a saturated solution. Acetic acid in the proportion of one part may also be added to the solution of the alkalis, if a slight solvent for the gelatin is required and during the incorporation of the mixed alkalis and the acid in the gelatinous mass a thorough agitation of the ingredients should be maintained in order to prevent all lumps from forming. When these ingredients are properly commingled the mass is tinted a light blue, as at 12, by mixing therein a suitable transparent blue coloring matter. As such a comparatively slight amount. of acetic acid is used, and as such acid is of a weak variety, there will be substantially no important chemical action produced by the combination of the acid and the alkali.

Before the mass has hardened it is formed into a plate of a desired size and thickness by the use of a mold, or other means, and the screen when finished may be mounted in a suitable frame, or support, as 13, for per- Initting moving pictures either in natural colors, or in black and white effects to be projected thereon from its rear, or from ts front during daylight, or in the dark, and in instances when the fabrication of the screen Patented Aug. 30, 1921.

tends to be too opaque it may be suitably I nate to a large extent the danger of fire during the exhibition of the pictures particu larly by providing for a rear projection thereon, and which will tend to modify the sharp high lights of the photography of the pictures by these high lights being absorbed in the fabrication of the screen especially when bright colors are being projected. Moreover, the animated objects of the pictures will appear in pronounced stereoscopic effects as Well as being largely free of flickers.

\Vhile I have set forth in the foregoing description the use of particular kinds of alkalis and an acid, it will be understood that I may employ instead thereotany suitable materials for their purposes, and fur thermore the screen may also be produced with, or without the use of coloring matter.

Having thus described my invention, I claim as new and desire to secure by Letters Patent 1. A screen for exhibiting moving pic.- tures, in the form of a plate made of transparent gelatinous material, an alkali and an acid mixed in the material for converting the transparency of the material to a translucency, and a material for clarifying the translucency of the plate when of a pronounced opaqueness.

2. A screen for exhibiting moving pictures, in the form of a plate made of transparent gelatin, a mixture of bromid of potas sium, iodid of potassium, and acetic acid incorpora ted in the gelatin for converting the transparency of the gelatin to a translucency, a light blue coloring in the mixed ingredients, and a material for clarifying the translucency of the plate when of a pronounced opaqueness.

3. A screen for exhibiting moving pictures, in the form of a plate made of transparent gelatinous material. and an alkali and an acid mixed in the material for converting the transparency of the material to a translucency.

4. A screen for exhibiting moving pictures, in the form of a plate made of transparent gelatin. and a mixture of bromid of potassium, iodid of potassium and acetic acid incorporated in the gelatin for converting the transparency ofthe gelatin to a translucency.

This specification signed and witnessed this 7th day of ApriL A. D. 1919.

FREDERICK W. HOCHSTETTER.

'itnesses D. KoEPER, FREDERICK CRYER. 

